Detergent compositions containing n-(2-hydroxyalkyl)-omega-methyltaurine



3,474,038 DETERGENT COMl-USITIQNS CONTAINDIG N-(2-HYDROXYALKYL)-w-METHYLTAURINE Ralph Raymond Sepulveda, Bronx, N.Y., andFrank Vincent Cieri, Union City, N.J., assignors to Lever BrothersCompany, New York, N.Y., a corporation of Maine Filed Oct. 7, 1965, Ser.No. 493,804 Int. Cl. Clld 3/30, J/OZ, 1/38 US. Cl. 252-437 7 ClaimsABSTRACT OF THE DISCLQSURE A novel liquid detergent is disclosed inwhich N-(2- hydroxyalkyD-N-methyl taurines are employed as hydrotropingagents. Organic sulfate, sulfonates, nonionic and cationic detergentscan be prepared in homogeneous liquid formulations using the (I -CN-(2-hydroxyalkyl)- N-methyl taurines.

This invention relates to certain novel liquid detergent formulations.

The preparation of liquid detergents is a problem which has receivedconsiderable attention in the art. Generally, liquid detergents comprisethe combination of a minor portion of a detergent ingredient and a majorportion of water, the latter to provide liquidity. Further to supplementand to improve the detergent properties, it is common to includebuilders and foam improving agents. In the case of detergentcomposiitons designed for use in light-duty applications, organiccompounds, such as the alkylamides or alkylolamides, are frequentlyused, usually to improve the forming properties. In the case ofdetergents adapted for use in heavy-duty applications, an inorganicbuilder is provided, which commonly is of the phosphate type,particularly, the alkali-metal tripolyphosphates and the alkali-metalpyrophosphates. In addition to the principal detergent, builders andsuds boosters, other ingredients may be present in the liquid, such asviscosity controlling agents, soil-suspending agents, dyes, perfumes,colorants, optical brighteners, germicides, and the like, as well assalts present in the detergent as a result of the manufacturing process.

As is well known, a problem in the formulation of liquid detergents ofthe foregoing general description is obtaining a homogeneous liquidwhich is stable against separation into two or more liquid phases. Thephase separation problem has been particularly troublesome. Reduced toits simplest terms, the problem is to dissolve a sufficient amount ofthe detergent-active ingredients in a single-phase liquid to provide aconcentrate of adequate potency. The detergent components are frequentlyof limited solubility in water, and are liable to be salted Out byinorganic salts which may be present, such as the inorganic builders. Inmany liquid detergents, it is common to employ a minor amount of alcoholfor the purpose of solubilizin the organic component in the wateremployed as the major portion of the solvent. In other liquiddetergents, the lower alkyl-benzene sulfonates, such as sodium xylenesulfonate or sodium toluene sulfonates, have been used as hydrotropes.

According to the present invention, it has been found, surprisingly,that the salts of certain N-(2-hydroxyalkyl)- N-methyltaurines withwater-solubilizing cations exhibit unexpected hydrotroping activity, andmay be used for this purpose in detergent formulations.

Typical liquid detergent formulations to which the present invention isapplicable consist essentially of about 2% to about 35% of asurface-active organic detergent and a sufficient amount of Water toliquefy the formulanite States Patent G 3,474,038 Patented Oct. 21, 1969tion, the amount of the detergent being sufficient that a mixture havingat least two liquid phases normally would occur. (By employing thephrase consisting essentially of it will be understood that detergentadjuncts may be present, such adjuncts being Well known in the art formodifying variou properties of the detergent formulation but notchanging its essential detersive nature.) To such a detergentformulation is added from 2% to 35% of a C to C N (2 hydroxyalkyl)N-methyltaurine, the amount thereof relative to said detergent beingsufficient to yield a homogeneous mixture.

The present invention is of particular applicability to detergentformulations consisting essentially of from 2% to 35% of asurface-active organic detergent, a builder to improve the detergencyproperties of said detergent and sufficient water to liquefy theformulation, the amount of the detergent being sufiicient normally toyield a formulation having more than one liquid phase. It has been foundthat the presence of a builder, and especially the inorganic alkalinephosphates, tends to make the organic detergents more difficultlysoluble. As in the broad concept of the present invention, an amount ofa C to C N-(2-hydroxyalkyl)-N-methyltaurine is present, generally etween2% and 35% of the formulation, which is sufficient to render the liquidhomogeneous. As a rule, when a builder is present, the ratio ofN-(2-hydroxyalkyl)-N- methyltaurine to detergent necessary to obtain ahomogeneous liquid is greater in the prescence of a builder than in itsabsence.

In greater detail, detergent formulations generally representative ofthe present invention will contain:

(a) from about 2% to about 35% of a surface-active, organic detergentcompound selected from the group consisting of detergent salts oforganic, sulfonic, and sulfuric acids, nonionic condensates of ethyleneoXide having detergent properties and cationic detergent compoundscontaining a quaternary nitrogen atom in the molecule;

(b) from about 2% to about 35% of an N-(Z-hydroxyalkyl)-N-methyltaurinehaving from about 6 to 12 carbon atoms in the alkyl group, the Weightratio of said N-(Z- hydroxyalkyl)-Nmethyltaurine to said detergent (a)being between about :10 and 10:90, and the amount of saidN-(2-hydroxyalkyl)-N-methyltaurine being sufiicient to yield ahomogeneous liquid;

(c) from 0% to about 20% of an alkaline phosphate builder;

(d) from 0% to about 15% of an organic amide of the formula:

0 R, H Rr-C-N in which R contains from about 8 to about 18 carbon atomsand R and R are each selected from the group consisting of hydrogen,lower alkyl and lower hydroxyalkyl radicals containing up to about 5carbon atoms, there being no more than one hydrogen attached to thenitrogen; and

(e) water and miscellaneous ingredients, the balance to make In theforegoing formulation, as well as hereafter in the specification andclaims, all percentages are based on the weight of the completeformulation unless specifically stated to the contrary.

Various miscellaneous ingredients may be added to improve the propertiesof the detergent formulation but which do not change the essentialnature thereof. Usually not more than about 10% to 20% of theformulation will be composed of such ingredients; although largeramounts of miscellaneous ingredients may be present especially if theprincipal active ingredients contain significant amounts of more or lessinert impurities. Possible miscellaneous ingredients include, but arenot limited to, thickeners, fillers, soil suspending agents, dyes,perfumes, colorants, optical brighteners, germicides, opacifiers, andthe like.

In the detergent formulations of the present invention, the amounts andrelative proportions of detergents, builders and suds boosters will besuflicient to result normally in a multi-phase solution. Additionally,there is provided a hydrotroping agent which consists essentially ofN-(Z-hydroxyalkyl)-N-methyltaurine in an amount, between about 2% andabout 35% by weight of the finished detergent formulation, sufiicient toyield a homogeneous liquid. Generally there should be from 6 to 12carbon atoms in the alkyl group of the N-(2-hydroxyalkyl)-N-rnethyltaurine. It is contemplated that theN-(Z-hydroxyalkyl)N-methyltaurines of the present invention may be usedin combination with other hydrotropes. By the phrase consistingessentially of it is intended to include within the ambit of thisinvention combinations wherein the N-(Z-hydroxyalkyl)-N-methyltaurine ispresent in such an amount that but for its presence a multi-phase liquidwould be obtained.

As the principal detergent, any one or more of the well-knownsurface-active detergent compounds may be used. Three important classesof detergents are recognized.

The first important class is the anionic detergents. Typical anionicdetergents which may be used in the present invention are the salts ofthe water-solubilizing cations mentioned above with various organicacids containing from 8 to about 18 carbon atoms such as the sulfonatesand sulfates. The hydrophobic portion of the molecule generally ischaracterized by at least one alkyl, alkenyl, alkylaryl or alkenylarylradical containing between about 8 and 18 carbon atoms; however, thisportion may also contain other functional groups such as carboxyl orether groups.

A particularly important group of anionic detergents are thoseexhibiting good biodegradability. Generally the property ofbiodegradability is associated with linear fatty alkyl groups in themolecular structure.

The second class of useful detergents are the nonionic surface-activecompounds. Nonionic detergents are generally prepared by thecondensation of ethylene oxide with one or more organic compoundscontaining an active hydrogen. The commercially important nonionicdetergents are generally condensates of ethylene oxide with eitherhydroxy-containing hydrophobic organic compounds, e.g. polypropyleneglycol or fatty alcohols, or amino-containing organic compounds;however, many others have been proposed in the literature. Biodegradablenonionic detergents based on linear fatty alcohols are known and may beused in the present invention. As in the case of the anionic detergents,the organic compound may be either alkyl alkenyl, alkylaryl oralkenylaryl and contain other substituent groups, i.e. ether linkagessuch as in the polyoxypropylene-based compounds.

The third major class of detergents is the cationic detergents. These,in general, contain a quaternary nitrogen within the molecularstructure. In some cases, the nitrogen may be contained in a ringstructure.

The most important, and largest class of quaternary ammonium compoundsare of the structure:

in which each of R R R and R is selected from the group consisting ofhydrogen, alkyl radicals containing from 1 to 5 carbon atoms, alkyl andalkenyl radicals containing from 8 to about 18 carbon atoms andalkylaryl and alkenylaryl radicals containing from 8 to about 18 carbonatoms. Among R R R and R there should be between 1 and 3 high molecularweight groups (containing from 8 to about 18 carbon atoms). In the aboveformula X is a water-solubilizing cation of which many are known in theart. For example, the halides (especially Cl and Br), sulfates andmethane sulfates are common; although other anions are possible and areincluded within the scope of the present invention.

The following is but a partial list of detergents which may be employed:

Sodium coconut sulfate,

Potassium stearyl sulfonate,

Potassium lauryl glycerol ether sulfate,

The ammonium of the sulfates of C14C18 mixed fatty alcohols,

Triethanolamine alkyl sulfate derived from coconut oil,

Sodium dodecyl benzene sulfonate,

Sodium C C secondary alcohol sulfates,

The potassium salts of carboxy isethionates, derived from coconut oilfatty acids,

Alkyl alcohol-3 ethylene oxide sodium sulfate,

Polyoxyethylene-polyoxypropylene ethanols,

Lauryl alcohol condensed with 6 moles of ethylene oxide,

Stearyl alcohol condensed with 10 moles of ethylene oxide,

C C mixed alkyl alcohols condensed with 9 moles of ethylene oxide,

Tall oil fatty acids condensed with ethylene oxide,

Ethylene diamine-propylene oxide-ethylene oxide condensates,

Dodecyl phenol-l0 ethylene oxide condensate,

Dodecyl trimethyl ammonium methosulfate,

Distearyl dimethyl ammonium chloride,

Dodecyl benzyl dimethyl ammonium bromide,

Cetyl pyridinium chloride.

The total amount of the detergent components will generally be betweenabout 2% and about 35 by weight. The present invention is specificallyconcerned with formulations in which the concentration of the detergentis in excess of the amount which will dissolve in a single liquid phasein the absence of a solubilizing agent. It will be recognized by thoseskilled in the art that the solubility characteristics of the varioussurface-active detergent compounds vary, and are affected by the othermaterials present in the detergent formulation. In some instances it maybe necessary to employ a solubilizing agent with as little as 2% of thesecond detergent present, especially if the formulation is built with aninorganic phosphate. In other cases, the detergent may be soluble to aconsiderably greater extent. Accordingly, the concentration of thedetergent which will require the presence of a hydrotrope will depend onthe nature of the detergent as well as the relative proportions ofdetergent and adjuncts.

The builders which are contemplated are the generally recognized solublealkaline phosphates, such as the alkali metal, pyrophosphates andpolyphosphates. Tetrasodium pyrophosphate, tetrapotassium pyrophosphate,sodium tripolyphosphate, potassium tripolyphosphates, and the simplesodium or potassium phosphates are the most common of the phosphatebuilders commercially available. The phosphate builders, when used, arecommonly pres ent in a concentration of from 5% to 20%.

In addition to or in lieu of the phosphate builders, organic buildersmay be used. Certain of the organic amides mentioned below, for example,are well known to be effective builders. Nitriloacetic acid salts areanother known group of organic builders which may be used in the presentinvention.

The organic amides contemplated have the following general formula:

R being a long-chain radical containing from about 8 to about 18 carbonatoms and R and R each being selected from the group consisting ofhydrogen, lower alkyl and lower hydroxyalkyl. There should be no morethan one hydrogen attached to the nitrogen atom. Typical compoundsinclude, but are not limited to, coco diethanol amide, and lauricisopropanol amide. Commonly the amides are employed for the purpose ofimproving the foaming or detergency properties of the formulation. Theorganic amides, when used, are conventionally present in a concentrationbetween about 2% and about 15%.

In addition to the foregoing principal ingredients of the composition,there may also be included the minor constituents typical of mostdetergent formulations. These minor constituents include thickeners,fillers, soil suspenders, dyes, optical brighteners, colorants,perfumes, germicides, etc. Sodium bicarbonate is Well-known as athickener. Sodium and potassium chloride are also effective for thispurpose. A number of cellulose derivatives, such as carboxymethylcellulose, carboxyethyl cellulose, carboxyhydroxyethyl cellulose and thelike are wellknown soil suspenders. Sodium silicates may be included,especially because of their value as corrosion retardants. Otherconstituents contemplated are the by-product salts which may be presentas a result of the process by which the detergent is prepared. Mostcommonly these salts are the alkali metal or ammonium salts of thehalogen acids or of sulfuric acid.

The salts of the N-(Z-hydroxyalkyl)-N-methyltaurines which are used ashydrotropes in the present invention have the following formula:

in which R; may contain from 4 to about carbon atoms, and M is awater-solubilizing cation. For most effective hydrotroping activity, theC -C N-(Z-hydroxyalkyl)- I-methyltaurine are preferred, (i.e. wherein Rin the above formula contains from 4 to 8 carbon atoms). As is wellknown in the detergent art, the water-solubilizing cations normally arethe alkali metal ions, ammonium, and substituted ammonium ions. Forcommercial economy and convenience, sodium, potassium and ammonium arethe preferred cations. Typical substituted ammonium ions known in theart include trimethylamm'onium, triethanolammonium and morpholiniumions. The alkyl group of the N-(Z-hydroxyalkyl)-N-methyltaurines may beeither straight or branched chain and may be derived from eithersynthetic or natural sources. Typical compounds include, but are notlimited to the sodium salts of N-(Z-hydroxyalkyl)-N-methyltaurines, inwhich the radical R is C C or C or mixtures of the foregoing.

The amount of the N-(Z-hydroxyalkyl)-N-methyltaurine should besufiicient to convert the detergent formulation into a homogeneousliquid stable against phase separation. Between 2% to 35% will usuallybe needed. The relative amount of the N-(Z-hydroxyalkyl)-N-methyltaurineto the second detergent may vary widely. In the broadest concept of thisinvention, a weight ratio between about 90:10 to 10:90 ofN-(2-hydroxyalkyl)-N- methyltaurine to the second detergent will be usedto obtain commercially useful improvements in the solubility of thedetergent. For the most effective hydrotroping activity, a weight ratioof N-(Z-hydroxyalkyl)-N-methyltaurine to the second detergent betweenabout 90: 10 and 50:50 is preferred.

Example 1 Percent Sodium salt of N (2 hydroxyoctyl) N methyl taurine 24Sodium lauryl sulfate 6 Water 70 Example 2 Sodium salt of N (2hydroxyoctyl) N methyl taurine 12 Sodium Alfol 14124.1 E.O. sulfate 18Water 70 1A straight chain primary alcohol, obtained by liquidpolymerization of ethylene, containing an average of 12 to lei: carbonatoms in the alkyl group and containing an average of about 3.1 ethyleneoxide groups.

The formulations illustrated in Examples 1 and 2 are each clearhomogeneous liquids.

As already mentioned, the compositions of the N-(2-hydroxyalkyl)-Nmethyltaurine (HAMT) plus a second detergent may be usedin conjunction with various builders. Liquid detergent compositionsillustrating the foregoing are as follows:

Example 3 Percent by Weight Ingredients A B 62.5. Description ofcomposition Opaque liquid Clear homoslight organic geneous separation atliquid. surface of liquid.

B Sodium N-rnethyl-N-coconut acid taurate.

Example 4 Percent by Weight Ingredients A B Cm HAMT l- 8. Polypropylenebenzene suli'onate a 2 2. Sodium tripolyphosphate..- 5.. 5. Water 93...85. Description of composition Orga s Clear homoprecipitate geneous.from liquid.

a Mole weight of sulionic acid is 325.

Example 5 Percent by Weight Ingredients A B Cw HAMT 8 LHES l0... Tetrapotassium pyrophosphate 20 Water 70 62.

Description of composition Transparent liquid, Clear LHES separates ashomosolids at top and geneous within liquid. liquid.

' Sodium lauryl glycerol ether sulionate.

Example 6 Ingredients: Percent by wt.

Potassium dodecyl benzene sulfonate, alkane sulfonic acids 9.62 Sodiumxylene-toluene sulfonate 7.93 Laurie isopropanolamide 3.11 Lauricdiethanol amide 2.67 Tetrapotassium pyrophosphate 18.58

Water to 100%.

Example 7 Sufiicient N-(2-hydroxyalkyl)-N-methyltaurine is added to amixture of 100 parts of the above liquid laundry detergent and about 5parts of distearyl dimethyl ammonium chloride to yield a homogeneousliquid. Without N-(Z-hydroxyalkyl)-N-methyltaurine a multi-layerseparation occurs.

Parts Ingredients A. B

Liquid laundry detergent 100 100 Cg HAMI Distearyl dimethyl ammoniumchloride 5 5 Water 15 Description of composition Clear Multi-layer hommseparation geneous liquid It will be understood that the examples arefor illustrative purposes only and are not intended to limit the spiritor scope of the invention and claims herein.

We claim:

1. A liquid detergent composition consisting essen tially of:

(l) a water-soluble salt of an N-(Z-hydroxyalkyD-N- methyl taurinehaving from about 6 to about 12 carbon atoms in the alkyl group;

(2) a second organic surface-active material having detergentproperties, said second detergent material being selected from the groupconsisting of detergent salts of organic sulfonic and sulfuric acidscontaining between about 8 and 18 carbon atoms, nonionic condensates ofethylene oxide having detergent properties and cationic organiccompounds having detergent properties and containing a quaternarynitrogen atom in the molecule; and

(3) the balance of said composition consisting essentially of water inan amount sufficient to yield a liquid-detergent composition;

the amount of said second organic surface-active detergent materialrelative to the amount of said Water being sufiicient that a liquiddetergent containing more than one phase would result in the absence ofsaid -N-(Z-hydroxyalkyD-N-methyl taurine, and the amount of saidN-(Z-hydroxylalkyl)-N-methyl taurine being between about 2% and about35% by weight of said Water, and suflicient to yield a homogeneousliquid.

2. A liquid detergent composition consisting essentially of:

(1) an N-(Z-hydroxyalkyl)-N-methyl taurine having from about 6 to about12 carbon atoms in the alkyl p;

(2) at least one second organic surface-active detergent compoundselected from the group consisting of detergent salts of organicsulfonic and sulfuric acids, nonionic condensates of ethylene oxidehaving detergent properties and cationic organic compounds havingdetergent properties and containing a quaternary nitrogen in themolecule;

(3) a builder to improve the detergency of said second organicsurface-active detergent compound; and

(4) the balance of said detergent composition consisting essentially ofwater in an amount suflicient to yield a liquid-detergent composition;

the amounts of said second organic surface-active detergent compoundsand said builder, relative to the amount of said water, being sufiicientthat a liquid detergent containing more than one phase would result inthe absence of said N-(2-hydroxyalkyl)-N-methyl taurine, and the amountof said N- (2-hydroxyalkyl)-N-methyl taurine being between about 2% andabout 35% by weight of said detergent composition, and sufiicient toyield a homogeneous liquid.

3. A liquid-detergent composition consisting essentially of:

(1) from about 2% to about 35% by weight of anN-(Z-hydroxyalkyl-N-methyl taurine having from about 6 to about 12carbon atoms;

(2) from about 2% to about 35% by weight of at least one secondsurface-active organic detergent compound selected from the groupconsisting or detergent salts of organic sulfonic and sulfuric acids,nonionic condensates of ethylene oxide having detergent properties andcationic detergent compounds containing a quaternary nitrogen atom inthe molecule;

(3) from about 0% to about 20% by weight of an alkaline phosphatebuilder;

(4) from about 0% to about 15% by weight of an organic amide of theformula in which R is a long chain acyclic aliphatic hydrocarbon radicalhaving from 8 to about 18 carbon atoms, and R and R are each selectedfrom the group consisting of hydrogen, lower alkyl and lower hydroxyalkyl radicals having up to about 5 carbon atoms, there being no morethan 1 hydrogen attached to the nitrogen; and

(5) the balance of said composition consisting essentially of Water, theamount of said water being suiticient to yield a liquid formulation;

the amount of said second organic detergent compound, alkaline phosphatebuilder, when present, and organic amide, when present, being suflicientthat a multiphase liquid detergent would result in the absence of saidN-(Z-hydroxyalkyl)-N-methyl taurine, and the weight ratio of saidN-(2-hydroxyalkyl)-N-methyl taurine to said second detergent (2) beingbetween 10 and 10:90, and sufficient to yield a homogeneous liquid.

4. A detergent composition in accordance with claim 3 containing fromabout 2% to about 15% of said organic amide.

5. A detergent composition according to claim 3 containing from about 5%to about 20% of said alkaline phosphate builder.

6. A detergent composition according to claim 3 wherein the weight ratioof said N-(2-hydroxyalkyl-N-methyltaurine to said detergent is betweenabout 90:10 and 50:50.

9 M) 7. A detergent composition according to claim 3 Where- FOREIGNPATENTS in said N-(2-hydroxya1kyl)-N-methyltaurine contains 1,332,7546/1963 France from about 6 to about 10 carbon atoms in the alkyl group.LEON D. ROSDOL, Primary Examlner Refer n e Ci g 5 S. D. SCHWARTZ,Assistant Examiner UNITED STATES PATENTS U.S. Cl. X.R.

3,254,028 5/1966 Wixon 252137 252-438, 152; 260-513 Patent; BA 4,038Dated: Qctober 21, 1969 Inventor(s) R R. Sepulveda et a1 It is certifiedthat error appears in the aboveidentified patent and that said LettersPatent are hereby corrected as shown below:

In the specification, column 1, line 3 "forming" should read "foaming".

In the claims, column 8, line 73, a parenthesis I: should be insertedafter "(2-hydr'oxyalkyl".

bihiti) Mill SEALED FEB 1 71970 (SEAL) Atteat:

WILLIMI I. "S-GHUYLER, JR- Edmu member Oomissioner of Patents AtmtingOfficer

